The Tui Chub (Gila bicolor)
If you pursue western Brown Trout then you need to learn all you can about two main forage items… the Kokanee Salmon and the Tui Chub. Big brown trout love to eat these two bait fish and if you can figure out the life cycle, feeding habits, movement patterns and any other clue to their whereabouts then it gives you that much more ammo for your brown trout game. For today’s article I will focus on the Tui Chub.
Brown Trout are eating machines. If you have ever fished for tuna you know that if you find the bait balls of ‘dines or ‘chovies.… the tuna are not far away. Brown trout are the same way. If your target lake has Tui Chub in it then you can be sure the Brown Trout will follow them throughout the year. Tui Chub are a schooling fish and form “bait balls” during certain times of year that concentrate them and allow the marauding browns an easy target. If you ever observe bait balls of Tui Chub and water temps are good for browns then you should troll or cast in the areas of those bait balls. Rest assured that there will be browns working the chub at various times of the day/night.
The Tui Chub will move around the lake quite a bit during the season and even throughout the day as they follow their own needs in regards to forage and spawning. Some feed on macroinvertebrates but most are plankton feeders and will follow the plankton throughout the day as they migrate up the water column, usually in the evening hours. They feed on many of the same items as any small salmonid would. Chub typically are deep during the winter and as the water warms they ball up and move shallow. They typically spawn in the late spring/summer but their timing depends on the lake elevation and depth, which dictates the water temps. They will typically spawn when water temps hit the mid-60s in the shallows but there is some variation.
Tui Chub are prolific breeders and can out-compete salmonids if the fishery is not managed properly. Lakes with an over-abundance of chub can be managed with piscivorous species of trout including browns, certain types of cutthroat and strains of Rainbow Trout like the Klamath Lake Rainbow which has adapted to eating large fin-fish, forage items.
An example of this stocking strategy is Lake Davis in Oregon. The Tui Chub had begun to out-compete the Davis Rainbow Trout in the glory days of the 1990s and early 2000s so the Oregon Department of Fish and Wildlife began to stock Klamath strain rainbows. These rainbows are chub eating machines and the plan seemed to be working as the rainbows began to reach epic proportions a few years after introduction. I personally netted a monster that was in the 16-18 pound range and caught many 5-10 pound fish that were chasing the chub. I will never forget one magical day where we were sticking 30 inch fish in 5 foot of water as marauding rainbows slashed through bunched up balls of chub… the chub jumping out of the water in unison as the monsters charged through the schools. It looked and sounded like it was hailing when they would jump out of the water all at once.
Although Tui Chub can reach large sizes of over 12 inches, browns like them in the smaller variety so don’t get too hung up on “big bait = big fish” mentality. I have found a Brown Trout dead with a large chub stuck in its throat. Once the chub get too big they are hard to digest and big browns will pass them up for their smaller, easier to catch and eat, cousins.
There are a variety of sub-species and subtle color variations with Tui Chub so connect with your local fisheries biologist to get some pics and size ranges for your favorite lake. Many biologists perform regular sampling of trophy lakes to manage population densities and will have this data available to the public. This will allow you to “match the hatch” with your favorite hardbait or crankbait next trip out. Don’t be afraid to cast to areas of schooling chub as this will allow your lure to be in the premium strike zone for concentrated periods of time. I have personally landed many nice browns using this method.
I hope this article gave you some tidbits of info about the Tui Chub that will help bring your trophy trout game to the next level. The Tui Chub is a very important food item to western Brown Trout and certainly we should do what we can to understand it. Look for an article in the future covering the most important food item for western Brown Trout… the Kokanee Salmon!
Mark Knoch
